684136 has 8 divisors (see below), whose sum is σ = 1282770. Its totient is φ = 342064.

The previous prime is 684127. The next prime is 684157. The reversal of 684136 is 631486.

It can be written as a sum of positive squares in only one way, i.e., 481636 + 202500 = 694^2 + 450^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

684136 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42751 + ... + 42766.

2⁶⁸⁴¹³⁶ is an apocalyptic number.

It is an amenable number.

684136 is a deficient number, since it is larger than the sum of its proper divisors (598634).

684136 is a wasteful number, since it uses less digits than its factorization.

684136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85523 (or 85519 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 684136 is about 827.1251416805. The cubic root of 684136 is about 88.1145203238.

Subtracting from 684136 its reverse (631486), we obtain a triangular number (52650 = T₃₂₄).

It can be divided in two parts, 684 and 136, that added together give a triangular number (820 = T₄₀).

The spelling of 684136 in words is "six hundred eighty-four thousand, one hundred thirty-six".